OBJECTIVETo discuss the clinical ultiliazation and significance of microembolus detection by transcranial Doppler (TCD) sonography in intracranial stenosis-occlusive disease.

DATA SOURCESAll related articles in this review were mainly searched from PubMed published in English from 1996 to 2012 using the terms of microembolic signal, transcranial Doppler, intracranial stenosis, stroke.

STUDY SELECTIONOriginal articles and reviews were selected if they were related to the clinical utilization of microembolus detection in intracranial stenosis-occlusive disease.

RESULTSIntracranial stenosis is a significant cause of cerebral emboli, and microembolus detection by TCD sonography were widely used in exploring the mechanisms of ischemic stroke with intracranial stenosis (including the middle cerebral artery stenosis and the vertebral-basilar stenosis), evaluating the prognosis of acute stroke, evaluating the therapeutic effects, and predicting the recurrent events of stroke.

CONCLUSIONMicroembolus detection by TCD sonography plays an important role in the cerebral ischemic stroke patients with intracranial stenosis.

Coronary artery fractional flow reserve (FFR) is a critical physiological indicator for assessment of impaired blood flow caused by coronary artery stenosis. The wire-based invasive measurement of blood flow pressure gradient across stenosis is the gold standard for clinical measurement of FFR. However, it has the risk of vascular injury and requires the use of vasodilators, increasing the time and overall cost of interventional examination. Coronary imaging is playing an important role in clinical diagnosis of stenotic lesions, evaluation of severity of lesions, and planning of therapies. In recent years, the computation of FFR based on the physiological information of blood flow obtained from routinely collected coronary image data has become a research focus in this field. This technique reduces the cost of physiological assessment of coronary lesions and the use of pressure wires. It is beneficial to strengthen the physiological guidance in interventional therapy. In order to better understand this emerging technique, this paper highlights its implementation principle and diagnostic performance, analyzes practical problems and current challenges in clinical applications, and discusses possible future development.
Humans ; Coronary Vessels/diagnostic imaging* ; Fractional Flow Reserve, Myocardial ; Heart ; Constriction, Pathologic ; Coronary Stenosis/diagnostic imaging*

OBJECTIVETo assess the diagnostic value of CT enterography in patients with Crohn's disease.

METHODSMulti-detector CT enterography and small bowel follow-through were performed in 30 patients with Crohn's disease. The locations and characteristics of the intestinal and extra-intestinal lesions detected by both two techniques were compared.

RESULTSSkip lesions were diagnosed in 16 patients (53.3%) by CT enterography and in 9 patients (30%) by small bowel follow-through (P = 0.039). Mucosal changes were detected in 29 patients (96.7%) by CT enterography and in 18 patients (60%) by small bowel follow-through (P = 0.001). Among 11 patients whose small bowel follow-through did not show abnormal mucosal changes, 8 patients underwent endoscopy, which showed superficial ulcer with or without mucosal congestion and edema in 5 patients, mucosal congestion and edema in 2 patients, and mucosal erosion in 1 patient. CT enterography and small bowel follow-through consistently depicted fistula in 3 patients and had no significant difference in diagnosing intestinal stenosis. CT enterography also exclusively detected abdominal abscess in one patient.

CONCLUSIONSCT enterography is superior to small bowel follow-through in diagnosing the disease location and characteristics of Crohn's disease; furthermore, it can detect more extra-intestinal lesions. CT enterography has potential to replace small bowel follow-through as the imaging examination of choice for patients with Crohn's disease.

Objective To acquire cerebral blood flow (CBF) in patients with severe intracranial atherosclerotic stenosis with enhanced pseudo-continuous arterial spin labeling (e-pCASL) and compare it with the findings of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC PWI) and pseudo-continuous arterial spin labeling (pCASL). Methods A total of 39 consecutive patients with severe intracranial atherosclerotic stenosis were enrolled in this study. All these patients underwent e-pCASL, pCASL, and DSC PWI. Blood supply territory of the stenosed artery was outlined as region of interest (ROI) and a mirror ROI was applied. Ratios of CBF were calculated as value of ROI/value of mirror ROI. SNK variance analysis was conducted to compare the CBF values of three persufion methods. Factorial analysis of variance and Pearson were employed to analysis the difference and the correlation of e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI relative cerebral blood flow(rCBF) ratio. Results The e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI rCBF ratio were not significantly different (P=0.476). TTP showed the CBF ratios were not significantly different between the healthy side and diseased side in patients with severe intracranial atherosclerotic stenosis. ATT showed the correlations of pCASL CBF ratio and DSC PWI rCBF ratio were not affected by ATT. Conclusions e-pCASL with multiple-post labeling delay time and pCASL have good consistency with DSC PWI in the quantitative measurement of hypoperfusion pattern. As an accurate, simple, non-invasive, and repeatable technique, e-pCASL has good correlation with DSC PWI in the quantitative measurement of hypoperfusion pattern that is not affected by ATT.
Cerebrovascular Circulation ; Constriction, Pathologic ; Humans ; Intracranial Arteriosclerosis ; diagnostic imaging ; Perfusion Imaging ; Spin Labels

Although the causes of hypertension are usually unknown, about 10% of the cases occur secondary to specific etiologies, which are often treatable. Common categories of secondary hypertension include renal parenchymal disease, renovascular stenosis, vascular and endocrinologic disorders. For diseases involving the renal parenchyma and adrenal glands, ultrasonography (US), computed tomography (CT) or magnetic resonance (MR) imaging is recommended. For renovascular stenosis and vascular disorders, Doppler US, conventional or noninvasive (CT or MR) angiography is an appropriate modality. Nuclear imaging can be useful in the differential diagnosis of endocrine causes. Radiologists should understand the role of each imaging modality and its typical findings in various causes of secondary hypertension. This article focuses on appropriate imaging approaches in accordance with the categorized etiologies leading to hypertension.
Adrenal Glands ; Angiography ; Constriction, Pathologic ; Diagnosis, Differential ; Diagnostic Imaging ; Humans ; Hypertension* ; Magnetic Resonance Imaging ; Ultrasonography

Central lung cancer is a common disease in clinic which usually occurs above the segmental bronchus. It is commonly accompanied by bronchial stenosis or obstruction, which can easily lead to atelectasis. Accurately distinguishing lung cancer from atelectasis is important for tumor staging, delineating the radiotherapy target area, and evaluating treatment efficacy. This article reviews domestic and foreign literatures on how to define the boundary between central lung cancer and atelectasis based on multimodal images, aiming to summarize the experiences and propose the prospects.
Humans ; Lung Neoplasms/diagnostic imaging* ; Pulmonary Atelectasis/complications* ; Bronchi ; Constriction, Pathologic/complications* ; Multimodal Imaging

Brain Infarction ; diagnostic imaging ; pathology ; Computed Tomography Angiography ; Constriction, Pathologic ; diagnostic imaging ; pathology ; Humans ; Male ; Medulla Oblongata ; diagnostic imaging ; pathology ; Middle Aged ; Vertebral Artery ; diagnostic imaging ; pathology

To investigate the feasibility and clinical effects of the laparoscopic urinary tract reconstruction with intraoperative retrograde ureteroscopy-assisted technique for the treatment of complex ureteral stricture. 
 Methods: The clinical data of 16 patients with complicated ureteral stricture treated by the laparoscopic urinary tract reconstruction with intraoperative retrograde ureteroscopy-assisted technique from February 2016 to June 2018 were retrospectively analyzed. All 16 patients were iatrogenic stenosis. There were 4 cases of severe hydronephrosis in the affected side, 7 cases of moderate hydronephrosis, and 5 cases of mild hydronephrosis. According to the specific location and length of the ureteral stricture, the corresponding surgical method was selected. 
 Results: All patients successfully completed the operation without conversion to open surgery and organ injury. After the operation, the patients were followed up for 8-18 months. The hydronephrosis of all patients was relieved to varying degrees, and no ureteral restenosis occurred. 
 Conclusion: The laparoscopic urinary tract reconstruction with intraoperative retrograde ureteroscopy-assisted technique can accurately locate the stenosis segment, test the anastomosis effect, expand the inflammatory stenosis, and improve the end-to-end anastomosis of the distal ureteral stricture, which is a new and effective technique for the treatment of complex ureteral strictures.
Constriction, Pathologic ; Humans ; Laparoscopy ; Retrospective Studies ; Ureteral Obstruction ; diagnostic imaging ; Ureteroscopy

BACKGROUND AND OBJECTIVES: Sleep has five different periods manifested by changes in the EEG activity and certain behavioral correlates. It has been proposed that the upper airway mechanics would be influenced by sleep stage. Although several methods have been used to evaluate the regions over which the upper airway collapses during sleep, there were seldom reports about the changes of upper airway according to the sleep stage. The present study was conducted to determine the effect of sleep stage on the upper airway dynamics. MATERIALS AND METHOD: Using electron beam, we studied ten normal subjects who did not have any sleep-disordered breathing. Each patient being monitored with EEG was scanned while sleeping naturally. The images were acquired during light sleep, deep sleep and REM sleep during at least two full respiratory cycles. RESULTS: Upper airway collapse was increased with the progression of sleep, but the level of stenosis was relatively constant throughout the sleep. Sleep stage had differential effects on the upper airway size depending on the investigated site. CONCLUSION: Our data suggest that upper airway mechanics are influenced by each sleep stage. This would indicate that the study of either point of sleep or either site of airway in isolation may not allow a proper insight on the overall upper airway pathophysiology.
Airway Obstruction ; Constriction, Pathologic ; Diagnostic Imaging ; Electroencephalography ; Humans ; Mechanics ; Sleep Apnea Syndromes ; Sleep Stages* ; Sleep, REM

OBJECTIVE: To explore the genetic basis for three fetuses with duodenal atresia or stenosis detected by ultrasonography. METHODS: Clinical data of three fetuses identified at the Women's Hospital Affiliated to Zhejiang University School of Medicine between January 2021 and August 2022 were collected. Umbilical cord blood and amniotic fluid samples of the fetuses and peripheral blood samples of their parents were collected and subjected to G-banded chromosomal karyotyping and single nucleotide polymorphism array (SNP array) analysis. RESULTS: Prenatal ultrasound of the three fetuses revealed duodenal atresia or stenosis. No karyotypic abnormality was detected, whilst SNP array has identified 1.4 ~ 1.9 Mb duplications at 17q12 in all of them, which were all predicted to be pathogenic copy number variations (CNVs). CONCLUSION The 17q12 duplications probably underlay the duodenal atresia and stenosis in these fetuses, and chromosomal CNVs should be considered in duodenal atresia and stenosis.
Pregnancy ; Humans ; Female ; DNA Copy Number Variations ; Constriction, Pathologic ; Prenatal Diagnosis ; Fetus/diagnostic imaging* ; Chromosome Aberrations